High resolution spectroscopy of BaCH3(X̃2A1): Fine and hyperfine structure analysis

J. Xin, J. S. Robinson, A. J. Apponi, L. M. Ziurys

Research output: Contribution to journalArticlepeer-review

19 Scopus citations


The pure rotational spectrum of BaCH3(X̃2A1) in its ground vibrational state has been recorded using millimeter/submillimeter direct absorption techniques, the first spectroscopic information obtained for this molecule. The radical was created using Broida-type oven/d.c. discharge methods by the reaction of barium vapor and Sn(CH3)4. Twenty-eight rotational transitions of the main isotopomer 138BaCH3 were recorded, as well as five for 136BaCH3 and three for the 137BaCH3 species. Being a prolate symmetric top, K ladder structure was observed in all transitions for BaCH3, as well as fine structure splittings which arise from the unpaired electron in the molecule. For the 137Ba isotopomer, hyperfine interactions were also resolved, arising from the spin of the barium nucleus. The complete data set has been analyzed with a 2A Hamiltonian, and rotational, spin-rotational, and magnetic hyperfine/nuclear quadrupole parameters accurately determined. The fine and hyperfine structure constants established from this study suggest a predominantly ionic bond for BaCH3, but with a considerable covalent component. Structural parameters for BaCH3 derived in this work are consistent with those of other alkaline earth monomethyl species.

Original languageEnglish (US)
Pages (from-to)2703-2711
Number of pages9
JournalJournal of Chemical Physics
Issue number7
StatePublished - Feb 15 1998

ASJC Scopus subject areas

  • General Physics and Astronomy
  • Physical and Theoretical Chemistry


Dive into the research topics of 'High resolution spectroscopy of BaCH3(X̃2A1): Fine and hyperfine structure analysis'. Together they form a unique fingerprint.

Cite this